Nitric oxide (NO) gas, when inhaled, dilates blood vessels in the lungs, improving oxygenation of the blood and reducing pulmonary hypertension. Because of this, some provide nitric oxide as a therapeutic gas in the inspiratory breathing gases for patients with pulmonary hypertension.
Typically, inhaled NO is delivered in a carrier gas from a high pressure source (e.g., a pressurized cylinder) to the patient at, or near, ambient pressure by means of a respiratory tube for ICU ventilator bound/dependent or anesthesia patients or a nasal cannula for spontaneously breathing patients. Delivering an accurate and consistent dose to the patient through a nasal cannula can be particularly challenging when the flow rate is pulsatile, for example, because dilution of the dose can occur.
Accordingly, a need exists for new methods and apparatuses for preventing dilution of dosing within the delivery conduit of a nitric oxide delivery apparatus, as well as methods of manufacturing such apparatuses.